Now I dont know if this is a crazy idea for fixed gear or not, these are really for BMX, I'm new to fixed gear, but these are threaded sockets. They are called Primo Jewels. One end is threaded, the other just fits a ratchet, no socket needed. These hold SUPER TIGHT. They hold rediculously tight. they are what you would use on a bmx bike when you have problems with your wheel shifting or you have a stripped axle and no other nut will hold tight. they are really great. I'll be putting a pair on my fixie when I get it together hopefully this weekend. I dont see the wheel moving with them on it. Primo Jewels Check them out. they're only 7 dollars a pair.